Bio-profiling and bio-prognostication of chronic heart failure with mid-range ejection fraction

Background Recent ESC guidelines on heart failure (HF) have introduced a new phenotype based on left ventricular ejection fraction (LVEF), called the mid-range (HFmrEF). This phenotype falls between the classical reduced (HFrEF) and preserved (HFpEF) HF phenotypes. We aimed to characterize the HFmrEF biomarker profile and outcomes. Methods 1069 consecutive ambulatory patients were included in the study (age 66.2 ± 12.8 years); 800 with HFrEF (74.8%), 134 with HFmrEF (12.5%), and 135 with HFpEF (12.5%). We measured serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), soluble suppression of tumorigenicity (ST2), galectin-3, high-sensitivity C-reactive protein, cystatin-C, neprilysin, and soluble transferrin receptor, during 4.9 ± 2.8 years of follow-up. The primary end-point was the composite: cardiovascular death or HF-related hospitalization. We also examined all-cause, cardiovascular death, and the composite: all-cause death or HF-related hospitalization. Results NTproBNP levels in HFmrEF were similar to levels in HFpEF, but significantly lower than levels in HFrEF. No other studied biomarkers were different between HFmrEF and HFrEF. All biomarkers, except neprilysin, showed higher risk prediction capabilities in HFmrEF than in HFrEF or HFpEF. The largest difference between HFrEF and HFmrEF was the hs-TnT level (hazard ratio [HR]: 4.72, 95% CI: 2.81–7.94 vs. HR: 1.67, 95%CI: 1.74–1.89; all p < 0.001). Conclusions Although HFmrEF is acknowledged as an intermediate phenotype between HFrEF and HFpEF, from a multi-biomarker point of view, HFmrEF was similar to HFrEF, except that NTproBNP levels were lower. Biomarkers commonly used for HFrEF risk prediction are more valuable for HFmrEF risk stratification.